kernel/block/blk-zoned.c, branch linux-6.19.y

block: Fix an error path in disk_update_zone_resources()

2026-01-19T18:04:06Z

Any queue_limits_start_update() call must be followed either by a queue_limits_commit_update() call or by a queue_limits_cancel_update() call. Make sure that the error path near the start of disk_update_zone_resources() follows this requirement. Remove the "goto unfreeze" statement from that error path to make the code easier to verify. This was detected by annotating the queue_limits_*() calls with Clang thread-safety attributes and by building the kernel with thread-safety checking enabled. Without this patch and with thread-safety checking enabled, the following error is reported: block/blk-zoned.c:2020:1: error: mutex 'disk->queue->limits_lock' is not held on every path through here [-Werror,-Wthread-safety-analysis] 2020 | } | ^ block/blk-zoned.c:1959:8: note: mutex acquired here 1959 | lim = queue_limits_start_update(q); | ^ Cc: Damien Le Moal Cc: Christoph Hellwig Fixes: bba4322e3f30 ("block: freeze queue when updating zone resources") Signed-off-by: Bart Van Assche Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20260114192803.4171847-3-bvanassche@acm.org Signed-off-by: Jens Axboe

block: fix cached zone reports on devices with native zone append

2025-12-10T05:35:54Z

When mounting a btrfs file system on virtio-blk which supports native Zone Append there has been a WARN triggering in btrfs' space management code. Further looking into btrfs' zoned statistics uncovered the filesystem expecting the zones to be used, but the write pointers being 0: # cat /sys/fs/btrfs/8eabd2e7-3294-4f9e-9b58-7e64135c8bf4/zoned_stats active block-groups: 4 reclaimable: 0 unused: 0 need reclaim: false data relocation block-group: 1342177280 active zones: start: 1073741824, wp: 0 used: 0, reserved: 0, unusable: 0 start: 1342177280, wp: 0 used: 0, reserved: 0, unusable: 0 start: 1610612736, wp: 0 used: 16384, reserved: 0, unusable: 18446744073709535232 start: 1879048192, wp: 0 used: 131072, reserved: 0, unusable: 18446744073709420544 Looking at the blkzone report output for the zone in question (1610612736) the write pointer on the device moved, but the filesystem did not see a change on the write pointer: # blkzone report -c 1 -o 0x300000 /dev/vda start: 0x000300000, len 0x080000, cap 0x080000, wptr 0x000040 reset:0 non-seq:0, zcond: 2(oi) [type: 2(SEQ_WRITE_REQUIRED)] The zone write pointer is 0, because btrfs is using the cached version of blkdev_report_zones() and as virtio-blk is supporting native zone append, but blkdev_revalidate_zones() does not initialize the zone write plugs in this case. Not skipping the revalidate of sequential zones in blkdev_revalidate_zones() callchain fixes this issue. Signed-off-by: Johannes Thumshirn Reviewed-by: Christoph Hellwig Reviewed-by: Damien Le Moal Fixes: a6aa36e957a1 ("block: Remove zone write plugs when handling native zone append writes") Signed-off-by: Jens Axboe

block: Clear BLK_ZONE_WPLUG_PLUGGED when aborting plugged BIOs

2025-12-04T22:43:28Z

Commit fe0418eb9bd6 ("block: Prevent potential deadlocks in zone write plug error recovery") added a WARN check in disk_put_zone_wplug() to verify that when the last reference to a zone write plug is dropped, this zone write plug does not have the BLK_ZONE_WPLUG_PLUGGED flag set, that is, that it is not plugged. However, the function disk_zone_wplug_abort(), which is called for zone reset and zone finish operations, does not clear this flag after emptying a zone write plug BIO list. This can result in the disk_put_zone_wplug() warning to trigger if the user (erroneously as that is bad pratcice) issues zone reset or zone finish operations while the target zone still has plugged BIOs. Modify disk_put_zone_wplug() to clear the BLK_ZONE_WPLUG_PLUGGED flag. And while at it, also add a lockdep annotation to ensure that this function is called with the zone write plug spinlock held. Fixes: fe0418eb9bd6 ("block: Prevent potential deadlocks in zone write plug error recovery") Cc: stable@vger.kernel.org Signed-off-by: Damien Le Moal Reviewed-by: Niklas Cassel Reviewed-by: Johannes Thumshirn Signed-off-by: Jens Axboe

block: fix NULL pointer dereference in disk_report_zones()

2025-11-13T16:10:04Z

Commit 2284eec5053d ("block: introduce blkdev_get_zone_info()") introduced the report_active field in struct blk_report_zones_args so that open and closed zones can be reported with the condition BLK_ZONE_COND_ACTIVE in the case of a cached report zone. However, the args pointer to a struct blk_report_zones_args that is passed to disk_report_zones() can be NULL, e.g. in the case of internal report zones operations for device mapper zoned targets. Fix disk_report_zones() to make sure to check that the args is not null before updating a zone condition for cached zone reports. Fixes: 2284eec5053d ("block: introduce blkdev_get_zone_info()") Reported-by: Shin'ichiro Kawasaki Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

block: fix NULL pointer dereference in blk_zone_reset_all_bio_endio()

2025-11-13T16:10:04Z

For zoned block devices that do not need zone write plugs (e.g. most device mapper devices that support zones), the disk hash table of zone write plugs is NULL. For such devices, blk_zone_reset_all_bio_endio() should not attempt to scan this has table as that causes a NULL pointer dereference. Fix this by checking that the disk does have zone write plugs using the atomic counter. This is equivalent to checking for a non-NULL hash table but has the advantage to also speed up the execution of blk_zone_reset_all_bio_endio() for devices that do use zone write plugs but do not have any plug in the hash table (e.g. a disk with only full zones). Fixes: efae226c2ef1 ("block: handle zone management operations completions") Reported-by: Shin'ichiro Kawasaki Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

blk-zoned: Move code from disk_zone_wplug_add_bio() into its caller

2025-11-12T21:05:23Z

Move the following code into the only caller of disk_zone_wplug_add_bio(): - The code for clearing the REQ_NOWAIT flag. - The code that sets the BLK_ZONE_WPLUG_PLUGGED flag. - The disk_zone_wplug_schedule_bio_work() call. This patch moves all code that is related to REQ_NOWAIT or to bio scheduling into a single function. Additionally, the 'schedule_bio_work' variable is removed. No functionality has been changed. Cc: Damien Le Moal Cc: Christoph Hellwig Signed-off-by: Bart Van Assche Reviewed-by: Damien Le Moal Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe

blk-zoned: Document disk_zone_wplug_schedule_bio_work() locking

2025-11-12T21:05:23Z

Document that all callers hold this lock because the code in disk_zone_wplug_schedule_bio_work() depends on this. Reviewed-by: Chaitanya Kulkarni Reviewed-by: Damien Le Moal Cc: Christoph Hellwig Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe

blk-zoned: Fix a typo in a source code comment

2025-11-12T21:05:23Z

Remove a superfluous parenthesis that was introduced by commit fa8555630b32 ("blk-zoned: Improve the queue reference count strategy documentation"). Reviewed-by: Chaitanya Kulkarni Reviewed-by: Damien Le Moal Cc: Christoph Hellwig Signed-off-by: Bart Van Assche Signed-off-by: Jens Axboe

block: introduce bdev_zone_start()

2025-11-07T16:28:08Z

Introduce the function bdev_zone_start() as a more explicit (and clear) replacement for ALIGN_DOWN() to get the start sector of a zone containing a particular sector of a zoned block device. Use this new helper in blkdev_get_zone_info() and blkdev_report_zones_cached(). Signed-off-by: Damien Le Moal Reviewed-by: Christoph Hellwig Reviewed-by: Bart Van Assche Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe

block: refactor disk_zone_wplug_sync_wp_offset()

2025-11-07T16:28:08Z

The helper function blk_zone_wp_offset() is called from disk_zone_wplug_sync_wp_offset(), and again called from blk_revalidate_seq_zone() right after the call to disk_zone_wplug_sync_wp_offset(). Change disk_zone_wplug_sync_wp_offset() to return the value of obtained with blk_zone_wp_offset() to avoid this double call, which simplifies a little blk_revalidate_seq_zone(). Signed-off-by: Damien Le Moal Reviewed-by: Bart Van Assche Reviewed-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe